Missing documentation on removeError and removeErrors

While going through the [READM on ember-changeset](https://github.com/poteto/ember-changeset) we noticed following lines:

```js
try {
await this.changeset.validate((changes) => FormSchema.validate(changes));
this.changeset.removeError(path); // << what is this method?
} catch (e) {
this.changeset.addError(e.path, { value: this.changeset.get(e.path), validation: e.message });
}
```

We tried to look for said function in [ember-changeset repo](https://github.com/poteto/ember-changeset/search?q=removeError), but apart from README and test, there were no results. Then we found out that said method is actually [defined on validated-changeset](https://github.com/validated-changeset/validated-changeset/blob/main/src/validated.ts#L432-L448).

But even the README of validated-changeset does not mention this method. By looking at the other methods of the `validated.ts` file, it seems like [validated-changeset README](https://github.com/validated-changeset/validated-changeset) is missing the documentation on `removeError` and `removeErrors`?

Open src/validated.ts at lines 432-448 and the validated-changeset README; compare the existing method documentation with removeError and removeErrors. Document both methods in the README, using their definitions to describe the behavior, and verify that the examples or API descriptions are consistent.

Scritto dal modello di indicizzazione a partire dal testo della issue.